Refactor some ResourceMessageReply usages.

content/renderer/pepper/pepper_device_enumeration_host_helper.cc

Index: content/renderer/pepper/pepper_device_enumeration_host_helper.cc
diff --git a/content/renderer/pepper/pepper_device_enumeration_host_helper.cc b/content/renderer/pepper/pepper_device_enumeration_host_helper.cc
index 28beb20936eca35601a28bf9018b655e21e0d87a..26ed02cedb30f63e65a2173c1f58822e0af550da 100644
--- a/content/renderer/pepper/pepper_device_enumeration_host_helper.cc
+++ b/content/renderer/pepper/pepper_device_enumeration_host_helper.cc
@@ -98,7 +98,8 @@ PepperDeviceEnumerationHostHelper::PepperDeviceEnumerationHostHelper(
     : resource_host_(resource_host),
       delegate_(delegate),
       device_type_(device_type),
-      document_url_(document_url) {
+      document_url_(document_url),
+      enumerate_devices_pending_(false) {
 }
 
 PepperDeviceEnumerationHostHelper::~PepperDeviceEnumerationHostHelper() {
@@ -135,7 +136,7 @@ int32_t PepperDeviceEnumerationHostHelper::InternalHandleResourceMessage(
 
 int32_t PepperDeviceEnumerationHostHelper::OnEnumerateDevices(
     HostMessageContext* context) {
-  if (enumerate_devices_context_)
+  if (enumerate_devices_pending_)
     return PP_ERROR_INPROGRESS;
 
   enumerate_.reset(new ScopedRequest(
@@ -145,8 +146,8 @@ int32_t PepperDeviceEnumerationHostHelper::OnEnumerateDevices(
   if (!enumerate_->requested())
     return PP_ERROR_FAILED;
 
-  enumerate_devices_context_.reset(
-      new ppapi::host::ReplyMessageContext(context->MakeReplyMessageContext()));
+  enumerate_devices_pending_ = true;
+  enumerate_devices_context_ = context->MakeReplyMessageContext();
   return PP_OK_COMPLETIONPENDING;
 }
 
@@ -170,15 +171,16 @@ int32_t PepperDeviceEnumerationHostHelper::OnStopMonitoringDeviceChange(
 void PepperDeviceEnumerationHostHelper::OnEnumerateDevicesComplete(
     int /* request_id */,
     const std::vector<ppapi::DeviceRefData>& devices) {
-  DCHECK(enumerate_devices_context_.get());
+  DCHECK(enumerate_devices_pending_);
 
   enumerate_.reset(NULL);
 
-  enumerate_devices_context_->params.set_result(PP_OK);
+  enumerate_devices_context_.params.set_result(PP_OK);
   resource_host_->host()->SendReply(
-      *enumerate_devices_context_,
+      enumerate_devices_context_,
       PpapiPluginMsg_DeviceEnumeration_EnumerateDevicesReply(devices));
-  enumerate_devices_context_.reset();
+  enumerate_devices_context_ = ppapi::host::ReplyMessageContext();
+  enumerate_devices_pending_ = false;
 }
 
 void PepperDeviceEnumerationHostHelper::OnNotifyDeviceChange(